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Marek Pruski - One of the best experts on this subject based on the ideXlab platform.

  • improved strategies for dnp enhanced 2d 1h x Heteronuclear Correlation Spectroscopy of surfaces
    Solid State Nuclear Magnetic Resonance, 2017
    Co-Authors: Takeshi Kobayashi, Umesh Chaudhary, Aaron D Sadow, Wenyu Huang, Igor I. Slowing, Frédéric A. Perras, Marek Pruski
    Abstract:

    We demonstrate that dynamic nuclear polarization (DNP)-enhanced 1H-X Heteronuclear Correlation (HETCOR) measurements of hydrogen-rich surface species are better accomplished by using proton-free solvents. This approach notably prevents HETCOR spectra from being obfuscated by the solvent-derived signals otherwise present in DNP measurements. Additionally, in the hydrogen-rich materials studied here, which included functionalized mesoporous silica nanoparticles and metal organic frameworks, the use of proton-free solvents afforded higher sensitivity gains than the commonly used solvents containing protons. We also explored the possibility of using a solvent-free sample formulation and the feasibility of indirect detection in DNP-enhanced HETCOR experiments.

  • studies of minute quantities of natural abundance molecules using 2d Heteronuclear Correlation Spectroscopy under 100 khz mas
    Solid State Nuclear Magnetic Resonance, 2015
    Co-Authors: Yusuke Nishiyama, Dilini Singappuliarachchige, Michal Maloň, Igor I. Slowing, Marek Pruski, Takeshi Kobayashi
    Abstract:

    Abstract Two-dimensional 1 H{ 13 C} Heteronuclear Correlation solid-state NMR spectra of naturally abundant solid materials are presented, acquired using the 0.75-mm magic angle spinning (MAS) probe at spinning rates up to 100 kHz. In spite of the miniscule sample volume (290 nL), high-quality HSQC-type spectra of bulk samples as well as surface-bound molecules can be obtained within hours of experimental time. The experiments are compared with those carried out at 40 kHz MAS using a 1.6-mm probe, which offered higher overall sensitivity due to a larger rotor volume. The benefits of ultrafast MAS in such experiments include superior resolution in 1 H dimension without resorting to 1 H– 1 H homonuclear RF decoupling, easy optimization, and applicability to mass-limited samples. The HMQC spectra of surface-bound species can be also acquired under 100 kHz MAS, although the dephasing of transverse magnetization has significant effect on the efficiency transfer under MAS alone.

  • spam mq hetcor an improved method for Heteronuclear Correlation Spectroscopy between quadrupolar and spin 1 2 nuclei in solid state nmr
    Physical Chemistry Chemical Physics, 2006
    Co-Authors: Jerzy W. Wiench, James Frye, Jean-paul Amoureux, Laurent Delevoye, Lionel Montagne, Gregory Tricot, Julien Trebosc, Marek Pruski
    Abstract:

    The recently introduced concept of soft pulse added mixing (SPAM) is used in two-dimensional Heteronuclear Correlation (HETCOR) NMR experiments between half-integer quadrupolar and spin-1/2 nuclei. The experiments employ multiple quantum magic angle spinning (MQMAS) to remove the second order quadrupolar broadening and cross polarization (CP) or refocused INEPT for magnetization transfer. By using previously unexploited coherence pathways, the efficiency of SPAM-MQ-HETCOR NMR is increased by a factor of almost two without additional optimization. The sensitivity gain is demonstrated on a test sample, AlPO4-14, using CP and INEPT to correlate 27Al and 31P nuclei. SPAM-3Q-HETCOR is then applied to generate 27Al–31P spectra of the devitrified 41Na2O–20.5Al2O3–38.5P2O5 glass and the silicoaluminophosphate ECR-40. Finally, the method allowed the acquisition of the first high resolution solid-state Correlation spectra between 27Al and 29Si.

Timothy A Cross - One of the best experts on this subject based on the ideXlab platform.

  • High-resolution Heteronuclear Correlation Spectroscopy in solid state NMR of aligned samples.
    Journal of Magnetic Resonance, 2007
    Co-Authors: Riqiang Fu, Milton Truong, Randy J. Saager, Myriam Cotten, Timothy A Cross
    Abstract:

    A new two-dimensional scheme is proposed for accurate measurements of high-resolution chemical shifts and Heteronuclear dipolar couplings in NMR of aligned samples. Both the 1 H chemical shifts and the 1 H– 15 N dipolar couplings are evolved in the indirect dimension while the 15 N chemical shifts are detected. This Heteronuclear Correlation (HETCOR) Spectroscopy yields high-resolution 1 H chemical shifts split by the 1 H– 15 N dipolar couplings in the indirect dimension and the 15 N chemical shifts in the observed dimension. The advantages of the HETCOR technique are illustrated for a static 15 N-acetyl-valine crystal sample and a 15 N-labeled helical peptide sam

Igor I. Slowing - One of the best experts on this subject based on the ideXlab platform.

  • improved strategies for dnp enhanced 2d 1h x Heteronuclear Correlation Spectroscopy of surfaces
    Solid State Nuclear Magnetic Resonance, 2017
    Co-Authors: Takeshi Kobayashi, Umesh Chaudhary, Aaron D Sadow, Wenyu Huang, Igor I. Slowing, Frédéric A. Perras, Marek Pruski
    Abstract:

    We demonstrate that dynamic nuclear polarization (DNP)-enhanced 1H-X Heteronuclear Correlation (HETCOR) measurements of hydrogen-rich surface species are better accomplished by using proton-free solvents. This approach notably prevents HETCOR spectra from being obfuscated by the solvent-derived signals otherwise present in DNP measurements. Additionally, in the hydrogen-rich materials studied here, which included functionalized mesoporous silica nanoparticles and metal organic frameworks, the use of proton-free solvents afforded higher sensitivity gains than the commonly used solvents containing protons. We also explored the possibility of using a solvent-free sample formulation and the feasibility of indirect detection in DNP-enhanced HETCOR experiments.

  • studies of minute quantities of natural abundance molecules using 2d Heteronuclear Correlation Spectroscopy under 100 khz mas
    Solid State Nuclear Magnetic Resonance, 2015
    Co-Authors: Yusuke Nishiyama, Dilini Singappuliarachchige, Michal Maloň, Igor I. Slowing, Marek Pruski, Takeshi Kobayashi
    Abstract:

    Abstract Two-dimensional 1 H{ 13 C} Heteronuclear Correlation solid-state NMR spectra of naturally abundant solid materials are presented, acquired using the 0.75-mm magic angle spinning (MAS) probe at spinning rates up to 100 kHz. In spite of the miniscule sample volume (290 nL), high-quality HSQC-type spectra of bulk samples as well as surface-bound molecules can be obtained within hours of experimental time. The experiments are compared with those carried out at 40 kHz MAS using a 1.6-mm probe, which offered higher overall sensitivity due to a larger rotor volume. The benefits of ultrafast MAS in such experiments include superior resolution in 1 H dimension without resorting to 1 H– 1 H homonuclear RF decoupling, easy optimization, and applicability to mass-limited samples. The HMQC spectra of surface-bound species can be also acquired under 100 kHz MAS, although the dephasing of transverse magnetization has significant effect on the efficiency transfer under MAS alone.

Julien Trebosc - One of the best experts on this subject based on the ideXlab platform.

  • spam mq hetcor an improved method for Heteronuclear Correlation Spectroscopy between quadrupolar and spin 1 2 nuclei in solid state nmr
    Physical Chemistry Chemical Physics, 2006
    Co-Authors: Jerzy W. Wiench, James Frye, Jean-paul Amoureux, Laurent Delevoye, Lionel Montagne, Gregory Tricot, Julien Trebosc, Marek Pruski
    Abstract:

    The recently introduced concept of soft pulse added mixing (SPAM) is used in two-dimensional Heteronuclear Correlation (HETCOR) NMR experiments between half-integer quadrupolar and spin-1/2 nuclei. The experiments employ multiple quantum magic angle spinning (MQMAS) to remove the second order quadrupolar broadening and cross polarization (CP) or refocused INEPT for magnetization transfer. By using previously unexploited coherence pathways, the efficiency of SPAM-MQ-HETCOR NMR is increased by a factor of almost two without additional optimization. The sensitivity gain is demonstrated on a test sample, AlPO4-14, using CP and INEPT to correlate 27Al and 31P nuclei. SPAM-3Q-HETCOR is then applied to generate 27Al–31P spectra of the devitrified 41Na2O–20.5Al2O3–38.5P2O5 glass and the silicoaluminophosphate ECR-40. Finally, the method allowed the acquisition of the first high resolution solid-state Correlation spectra between 27Al and 29Si.

Jerry C C Chan - One of the best experts on this subject based on the ideXlab platform.

  • Double-quantum filtered Heteronuclear Correlation Spectroscopy under magic angle spinning.
    Solid State Nuclear Magnetic Resonance, 2007
    Co-Authors: Yao Hung Tseng, Tim W T Tsai, Shih-hao Huang, Yi-ling Tsai, Jerry C C Chan
    Abstract:

    Abstract We present a simple experimental method to extract the van Vleck second moment of a multiple-spin system under high-resolution condition. The idea is to incorporate a double-quantum (DQ) filter into the pulse sequence of Heteronuclear Correlation Spectroscopy so that a DQ excitation profile can be obtained by measuring a series of 2D spectra. The effects of spinning frequency and proton decoupling are demonstrated on the measurements of two model compounds, viz. hydroxyapatite and brushite. Based on the results obtained for the model compounds, the P-31 homonuclear second moment of the apatite component in rat dentin is characterized. The method is generally suited for the study of bone, enamel and dentin.